1. Field of the Invention
This invention relates to a method for making a heat dissipating device, more particularly to method for making a heat dissipating device including a container body with a wick structure and a working fluid therein.
2. Description of the Related Art
FIG. 1 illustrates a conventional heat dissipating device, which is a flat plate-type heat pipe, useful for dissipating heat resulting from operation of an electronic component, such as a CPU, attached thereto. The heat dissipating device includes a container 1 with a container body 11 made from a metal and having heating and cooling ends 111, 112, a wick structure 12 formed in the container body 11, and a working fluid 13 filled in the container body 11. The wick structure 12 is formed with a network of capillaries 121. In use, the working fluid 13 at the heating end 111 is vaporized upon absorbing heat from the electronic component. The vapor thus formed flows from the heating end 111 toward the cooling end 112, and is subsequently condensed thereat, which, in turn, results in a liquid flow from the cooling end 112 toward the heating end 111 by virtue of the capillary mechanism of the capillaries 121 of the wick structure 12, thereby enabling automatic circulation of the working fluid 13 in the container body 11.
Since the liquid-vapor balance of the working fluid 13 in the container body 11 is critical to efficient heat dissipation, it is required that there be substantially no presence of air in the container body 11.
FIGS. 2 to 4 illustrate a conventional method for making the heat dissipating device. The method includes the steps of inserting a tube 14 into an opening 113 in the container body 11, sealing a clearance around the tube 14 by welding techniques, vacuuming the container body 11 through the tube 14, filling the container body 11 with the working fluid 13 through the tube 14, deforming the tube 14 to form a closure 141 so as to provide a temporary sealing for preventing air from entering into the container body 11, and immediately cutting the tube 14 such that the closure 141 remains on the container body 11 and then sealing an outer end 142 of the closure 141 with a sealing material.
Since the temporary sealing effect provided by the closure 141 thus formed is poor, air may enter into the container body 11 through slits formed in the closure 141 prior to the sealing operation of the closure 141, thereby adversely affecting the vapor-liquid balance of the working fluid 13 in the container body 11. As a consequence, the sealing operation is required to be conducted at the same apparatus where the deforming and sealing operations are performed, which considerably increases the cost of the apparatus.